"I was following it with great interest and I was very emotional … Discovery played a key role in helping us create the International Space Station, which is now our toehold on the universe for humans, and it was quite a historic vehicle," Bolden on CBS's "Face to Face."

Discovery was flown over Washington landmarks, including the Capitol, on Tuesday on its way to the National Air and Space Museum's Steven F. Udvar-Hazy Center in Chantilly, Va. NASA is retiring the shuttle, and three others, from its recently ended shuttle program.

ADVERTISEMENT

"Every day with shuttle is emotional for me," added Bolden

Bolden, who was an astronaut himself and flew on shuttle missions, said he hoped yesterday's display would show Americans that the shuttle is a "piece of our heritage."

The former astronaut was optimistic about the future for human space exploration.
He told CBS that despite the end of the shuttle program, the United States is using the Russian Soyuz to reach the space station and said there is a competition under way to choose a private company to carry astronauts in the United States into space.

"Humans have always wanted to go into deep space. We have never, ever been into deep space. We have never been any farther than the moon. We're going to go farther than the moon. We're going to go beyond that," he said.

"I'm not going to go there. I stay away from politics and political statements," said Bolden, laughing.

However, he added: "It is not unlikely that humans will be back on the surface of the moon … we don't colonize anywhere, but we will explore. Mars is one of our destinations."

The NASA chief said he predicts the United States will send humans to Mars within the next two decades.

"President Obama and I say we are going to have humans in the martian environment by 2030. We're saying that in a time of very strained economics because we have a plan to get us there and I think we're going to do it," Bolden said.

When asked how NASA will be able to handle potential cuts to its budget at a time when lawmakers are calling for fiscal austerity, Bolden said the agency will be able to carry out its mission because it works "collaboratively" with other parts of government like the National Oceanic and Atmospheric Administration and the Department of Defense.

"We produce technology … that's what we do. We have the people who develop the technologies, check them out and then turn them over to the people who are going to use them for operational uses," he said.

The House Appropriations Committee on Wednesday proposed cutting Commerce, Justice and Science-related agencies by $1.6 billion next year. A large chunk of savings comes from NASA — which faces a $226 million cut, mostly due to the end of the Space Shuttle program.